The fish is drawn with a brush tool. The highlights and shades with the dodge tool and burn tool. Fins are drawn and the drag tool used to spread them.
step 2 of 6
The fins were dragged out with the drag tool to give a feathery effect, then from about halfway to the end, and eraser was used at 25% to give the fins a sheer effect
step 3 of 6
The splash was drawn in and edges blurred slightly for softness. Highlighting and shading were done again with dodge and burn tool.
step 4 of 6
The fish and the "splash" are placed to look good, the duplicated to form a mirror image.
step 5 of 6
A bubble is made by drawing a dot and shading and highlighting.
These were duplicated and sized.
step 6 of 6
Background is added with blue swirls drawn on a slightly lighter background.